I'm late to seeing this for the OP, but I'd like to second the Mosher book, "Tasting Beer." It is excellent.
For cocktails, I think Jim Meehan's PDT book is indispensable. The Wondrich books--Imbibe and Punch--are great for history, but the recipes in there are mostly useful only as a history lesson. Not to knock those books: they're excellent. They're just not complete for today's bartender since 90% of the ingredients a bartender is using now, outside base spirits, citrus juice and a couple syrups, were not at the disposal of the pre-prohibition bartender. Meehan's PDT has a few hundred recipes, lessons on the distillation and flavor profiles of base spirits, liqueurs, etc., a primer in what you need to start your bar (home or professional), and a lot more. It's the book I'd give a someone as her or his first cocktail how-to.